Nailbrush



Oct. 25 1927.

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Patented Oct. 25, 1927.

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Applicationfiled March 31', 1925, Seria1 110. 19,709. "Renewed Afirll 7.1 927 This invention relates to brushes and particularly to brushes of the type having a core which is removable from the back or handle portion.

The object of the invention is to construct a brush having a recessed back and an elastic core, a transverse dimension of the latter being slightly greater than the corresponding dimension of the recess, said core being bendable archwise for insertion into said recess, and expanding through its inherent elasticity into contact with the walls of said recess, being in this manner retained in place, the relativ size of the recess and core being such that the condition of stress in said core produced by arching it, is not entirely relieved by its expansion into the recess, so that pressure upon the face of the brush incident to its use, tends further to flatten the arched core, augmenting the side thrust of the core against the walls of the recess and the more securely retaining the core in place.

Other objects'of the invention will appear as the following description of illustrative forms of the invention proceed.

In'the drawings Figure 1 is a side elevation partly in section showing a form of my invention.

Figure 2 is a section taken along the line Figure 3 is a section taken along the line 38 of Figure 1. Figure 4; is a detail view partly in section showing a slightly modified form of the invention. I

Figure 5 is a detail view in section showing still another form of the invention.

Referring now in detail to the several figures, the numeral. 1 represents the back or handle part of the brush and 2 the core which carries the bristles or filaments. In that form of the invention illustrated in Figure 1 the core is formed. of a strip of rubher out transversely along one edge into filaments 3, and rolled together, and vulcanized. The back or handle 1 is formed with a recess 4 into which the core is adapted to be inserted. Said core is made slightly larger in one of its transverse dimensions than the corresponding dimension of the recess so that in order to effect the insertion of said core into said recess it is necessary to bend the core into an arch shape as shown at 5 in Figure 1, placing it under stress. l/Vhen the core is inserted into the recess as shown, it expands, tending to reassume its condition of repose but is restrained by the side wall 6 of the recess against which wall it presses with a force sufiicient to retain the core securely within said recess. By this construction, pressure upon the face of the brush is transmitted as lateral stress against the side wall of the recess further augmenting the pressure between said core and the back of the brush may be instances, however, where an extraordinarily secure attachment is desired, in which cases it may be preferable to mold or otherwise form the recess with an undercut side wall as indicated at 7 in Figure 4.

'lVhile I prefer to form my improved brush with a core of laminated strip rubber having integral filaments, as above described the invention is by no'means limited to such construction, but numerous other forms and arrangements of structure. For instance, in Figure 5 I have illustrated the core as being made of an elastic rubber block 8 in which ordinary bristles of animal origin are embedded.

The invention lends itself readily to the construction of a brush in which the handle or backis of such ornamental or intrinsic value that it may be desired from time to time to replace the core without discarding the entire brush. For sanitary purposes, also, it is advantageous to have a brush, the inserted or filamentous portion of which may be removed for boiling in water, or other process of sterilization. It is an easy matter to grasp the core by the middle and to remove it from the handle, the core bending through its inherent elasticity and permitting easy withdrawal. The new core is inserted by pressing it at diametrically opposits points until it has arched convexly in the direction of its face to a suflicient degree to permit its insertion within the recess of the handle.

Having described my invention what I claim as new and desire to secure by Letters Patent, is 2- I A brush including a back formed with a recess, and a core having a filamentous face,

may be exemplified in said core being elastic and normally having a lateral dimension slightly exceeding the corresponding dimension of said recess, said core being compressed to arch the same outwardly and being seated in said recess, the

depth of the recess and the thickness of the core therewithin, exceeding the height of the crown of the arched inner face of the core, whereby the stress induced by the archlng of the core 18 transmitted through the score to the Walls of said recess in opposite directions, in lines of force which lie substantially in the sanie or parallel planes.

In testimony whereof I have hereunto set my hand.

ROBERT MORSE \VITHYCOMBE. 

